There are many benefits of manual transmissions over automatic transmissions. They are cheaper options in cars and they require less maintenance. For competent drivers, manuals offer more direct control of power to the ground which is increasingly helpful as road conditions stray from perfection. However, the one aspect guaranteed to put a smile on your face is the ability to clutch a dead engine. I give you, my fellow Everythingarians, the clutch start. Or, for our friends across the pond, the bump start.
The When
If you ever attempt to start your manual transmission car and the engine won't turn over, you're not out of the game yet. We can make that bitch fire up! Just make sure that your engine is healthy, which should be the case. We're only talking about a dead battery, right? Or maybe your starter solenoid went to that Big Junkyard in the Sky. Hell, the starter could have crapped out. Maybe the clutch cable stretched out and the clutch safety switch thinks that the clutch is still engaged. Long story short, there are plenty of things in the ignition system that can fail to start your engine when everything else is fine and dandy. Just as long as your engine has gas and oil, it's pretty safe to try this.
The How
You need one thing other than a manual transmission for this--potential energy. In the best case, you are parked on a hill. Something that would allow you to coast, without power, up to 10 mph or so. Alternatively, if you, with or without friends, can push your vehicle out of the driveway or down the street to such a hill, this can still work. It is not recommended that you attempt to push the vehicle up a hill unless you have a stout parking brake or you're just the brawniest motherfucker you've ever met. Or you just don't like the people that live downhill from your current location.
Either way, get your vehicle ready to roll. Make sure that the key is in the ignition and turned to the On position (where the key snaps back to after you unsuccessfully try to turn the engine over). Take the transmission out of gear and disengage the parking brake. If the car does not start rolling on its own accord, hang your foot out of the door and give it some help. Be advised that your car will NOT have power brakes or power steering until the engine is running. This will make stopping very difficult if you fail to start the engine--the emergency brake will be the only hope, short of a phone pole. Also, if you've never piloted a car without power steering . . . well, you better be a big sumbitch to control the car. Trust me.
Once the car starts rolling, make sure that your current direction won't result in a collision of some kind. If you find that you cannot steer the car, engage the parking brake immediately. I told you that you need some meat on your bones!
Now that you start picking up speed, put the transmission into first gear but keep the clutch disengaged (translation: pedal on the floor). You're going to engage the clutch, but not as fast as normal. Let up on the pedal until it starts to engage--your tachometer won't register any RPMs but you'll feel the car slow down a little. Now gradually release the clutch over two seconds, and I'm talking honest to God "one-Mississippi, two-Mississippi" seconds. Ideally, you'll want to start engage the clutch at about 1,500 to 2,000 RPMs. I know your tachometer is going to be at zero, but begin when you feel you are at the speed equivalent to 1,500 or 2,000 RPMs in first gear. Smaller engines will need fewer RPMs while V8 powerhouses may need to aim a little higher in that given range.
You'll know when it works--your forehead will have the imprint of your steering wheel or its cover. Be ready for the car to seemingly come to an instantaneous stop then immediately jump forward and continue down the road as if you were driving it normally. It's probably a good idea to immediately shift into neutral while you reacquire your bearings. But hooray, your engine is running thanks to a clutch start!
The Why
So how does it work and why? Well, in a simplified scenario, your engine creates power by turning the crankshaft. The crankshaft is connected to the transmission, so long as the clutch is engaged. The transmission is connected to the wheels by a driveshaft and axle in rear and all wheel drive vehicles or a transaxle in front wheel drive vehicles. Thus, power goes from the crankshaft to the transmission to the wheels in order to move your car.
However, in this case, the engine will not start. So no power goes through the transmission and to the wheels, right? That's where the hill comes in. By rolling down the hill, the potential energy of height is translated to kinetic energy. The car is moving, but more importantly, the wheels are turning. That means the axle is turning and so is the transmission. However, as long as either the clutch is disengaged or the transmission is in neutral, no kinetic energy is transferred to the engine.
You wait for that 1,500 or 2,000 RPM speed to build up so that you can put the transmission in gear and engage the clutch, thereby transferring the kinetic energy of the wheels to the engine. However, you need enough kinetic energy to overcome the coefficient of static friction as well as force the pistons to compress the air in the cylinders by a factor of nine or more.
The violent snap comes from the fact that the clutch disc is designed to absorb a certain level of RPMs. At first, you just burn away a little bit of clutch disc surface without transferring rotations to the engine. But when you fully engage the clutch, the engine is pretty much locked into synch with the transmission and you force the engine to turn. As it happens, you may go from zero to a thousand RPMs in about one second or less, so things start to happen quickly. Since the wheels are connected to the transmission and the transmission is now in synch with the engine, you're using the kinetic energy of the vehicle and its spinning wheels to impart rotation to the crankshaft. This forces the engines into life and self sustaining internal combustion takes over. It's just an instantaneous reversal of the norm--using your wheels to spin the engine, instead of the other way 'round.
This is not dangerous nor disastrous to your vehicle so long as you do not engage the clutch while traveling at too high of a speed. Therefore, only somewhat experienced drivers should attempt a clutch start. In addition to the need for safely engaging the clutch at a reasonable speed, the fact that the car will be without effective braking or steering until the engine is started requires a competent driver to be at the wheel.
Enjoy! Just another part of how to use a manual transmission. Note that this is most certainly NOT how to use an automatic transmission. Ever.
Footnote
I went with my dad to pick up his new Nissan pickup in '94 or so. The payments had been arranged and the paperwork had been previously signed so all we had to do that day was drive off with the truck. We get in the shiny white extended cab, breathed that new car smell and go to start the engine. No dice. Brand new truck and the damn battery is already dead! Fucking imports! Without a second thought (other than a nasty message for the salesman), my dad calmly released the parking brake and we glide down off the incline the truck was left on. One clutch start and a snap later, the engine is purring and we're motoring off into the distance. It was only later that evening that my dad, previously browsing the owner's manual, looked up to tell me that truck would not start thanks to an anti-theft device that was part of the ignition system on the steering column.
To which I can only say 1) fuck you, Mr. Salesperson and 2) I hope he didn't pay extra for that feature because it sure as shit didn't work.
Footnote 2.0
ponder reminds me that you do not have to do this in first gear. While that is something that slipped my mind, I will say that I have used other gears for a clutch start. So we know that we can start a dead engine once we have built up a little speed, right? Well, the beauty of a stick shift is that you can restart a dead engine when you're going 45 mph.
There was a time when my throttle position sensor was acting up and my engine would cut off as I went down the road. It actually happened when I was using a little bit of engine braking and then disengaged the clutch. Unfortunately, you use engine braking when you want to stop for stop lights, trains, little things like that. I tried to explain the problem to my dad and then we went about recreating it. My dad is flustered by nothing, so he jumped right into my knowing full well that we were trying to kill the engine while driving down the surface streets.
Remember that bit about having no brakes and no steering while the engine is off? And how the engine liked to die when I approached stop signs, stop lights and the like? Well, it did its trick the first time and we were hurtling into the back of a lane's worth of stopped cars at the light. I would say the engine was dead about 100 feet away from the last car. At 45 mph, you cover 66 feet per second, so we're talking 1.5 seconds to restart the engine and stop the car. Now, I could have reached for my keys, but by the time the engine turned over and I grabbed my Hurst shift knob, we'd be in the back seat of the car ahead of us. So using the same principle outlined in the writeup, I immediately put the transmission into third gear and quickly released the clutch. There was the usually snap forward and some tires barking for extra show, but the engine immediately sprang to life and I stopped the car with a few feet to spare. We drove all over town like that in an effort to repeat the problem and help the diagnosis. Even then it was just second nature to me, and I still never blink if my engine dies, I just go the appropriate gear and let go of the clutch. Presto, instant RPMs!
Disclaimer: clutch starting a dead engine as you hurtle down the road into traffic is much more dangerous than clutch starting an engine with a dead battery on a hill. DO NOT try this unless you are very good driver with a solid understanding of your engine, transmission, braking and steering. Recommended for emergency use only.